Vehicle seat presenting a back that can be folded down fowards

ABSTRACT

A vehicle seat comprising a back and a seat proper secured to a first rigid frame, the first frame being itself supported on both sides of the seat proper by a second rigid frame on which the back is pivotally mounted. The first frame is movable between a first position and a second position relative to the second frame. The first frame is connected to the second frame via at least one link. A locking device is adapted to block the first frame in the first position, and a linking mechanism is adapted to release the locking device while the back is being tilted down towards the seat proper.

FIELD OF THE INVENTION

The present invention relates to vehicle seats that take up less spacewhen in the folded position.

More particularly, the invention relates to a vehicle seat comprising aback and a seat proper comprising a cushion secured to a first rigidframe, the first frame being itself supported on both sides of the seatproper by a second rigid frame, the first frame being movable between afirst position and a second position relative to the second frame, thefirst frame incorporating a front portion and a rear portion, eachconnected to the second frame by means of at least one link, the linkpresenting firstly a bottom portion pivotally mounted on the secondframe and secondly a top portion pivotally mounted on the first frameand movable relative to the second frame from an initial position,corresponding to the first position of the first frame, to a retractedposition corresponding to the second position of the first frame, thelink being designed so that the second position of the first frame islower than the first position.

BACKGROUND OF THE INVENTION

A vehicle seat of the above-described type is disclosed in documentFR-A1-2 705 289, in which the seat proper moves backwards in order toretract the padding on this seat as far as possible and thus obtain ahorizontal stool (i.e. a folded-flat position)

However, this type of seat has the disadvantage of using a complex andbulky control system made up of a plurality of links, shafts, and slotsinvolving significant amounts of slack in control.

SUMMARY OF THE INVENTION

A particular object of the present invention is to mitigate thosedrawbacks.

To this end, according to the invention, a vehicle seat of the type inquestion is characterized by the fact that the back is pivotally mounteddirectly on the second frame, in that a locking device is adapted toblock the first frame in the first position, and in that a linkingmechanism is adapted to release the locking device while the back isbeing tilted down towards the seat proper.

By means of these dispositions, the seat proper of the seat can be movedforwards and lowered in order to provide a vehicle seat that is compactwhen it is in the folded position, i.e. when the back is folded downonto the seat, with no complex and bulky control linkage.

In various embodiment of the seat of the invention, one or more of thefollowing systems may optionally also be used:

the first frame is a sheet metal bucket;

the second frame comprises two cheekplates that surround the bucket;

the locking device comprises at least one blocking member pivotallymounted on the first frame to pivot between a blocking position in whichit holds one of the links in its initial position and a release positionin which it enables the link to move, the blocking member presenting acam surface on which the link slides, moving the member towards itsrelease position while the first frame is being moved towards the firstposition;

the seat includes a spring that urges the link towards its retractedposition;

the seat proper is supported by two front legs and two rear legs and inwhich each second frame is mounted on a front leg in such a way that itpivots;

the second position is further forwards than the first position;

the seat back can be folded down onto the seat proper in a substantiallyhorizontal stool position and in which the release of the locking deviceis achieved when the back is close to this stool position; and

the linking mechanism is a cable that extends between the back and thelocking device.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention become apparentfrom the following description of an embodiment given by way ofnon-limiting example and with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a side view of the seat of the invention in the deployedposition;

FIG. 2 is a view similar to FIG. 1 in which the seat is in the stoolposition;

FIG. 3 is a view similar to FIG. 1 in which the seat is in a folded-upposition; and

FIG. 4 is an exploded perspective view of a portion of the seat of theinvention.

MORE DETAILED DESCRIPTION

In the various figures, the same references designate elements that areidentical or similar.

The terms front, rear, top, and bottom are used in the description intheir usual meanings in connection with a vehicle.

The seat assembly of the invention is for use in vehicles such asminivans that offer increased load space when the seats are in thefolded-up position, as shown in FIG. 3. More particularly, the seatassembly of the invention can be used for so-called second and third rowseats, which must be highly versatile, and in particular must be capableof being folded down into a stool position (shown in FIG. 2) or of beingfolded up into an upright position such as the folded-up position (shownin FIG. 3) in which it provides a high-capacity trunk, or of beingtipped into a position in which the deployed seat together with its seatproper is pivoted to allow access to the space at the rear (not shown).

In the invention, the seat assembly comprises a seat 10 made up of aseat proper 12 that extends substantially longitudinally along the axisX inside the vehicle between a front part 14 and a rear part 16, and ofa back 18 that extends substantially vertically inside the vehicle whenthe seat is in the deployed position as shown in FIG. 1.

The back 18 is pivotally mounted relative to the seat proper 12 about atransverse axis Y1. The angle of inclination of the back 18 relative tothe seat proper 12 is adjustable by means of a discontinuous hinge ofthe type described in document FR-A1-2 740 406, which enables the hingeto be held in its unlocked position, even after its unlocking controlmember 20 has been released, for certain maneuvers of the back 18 suchas folding it down forwards onto the seat proper 12 in order to put theseat 10 into the stool position, shown in FIG. 2, or folding up the seatas shown in FIG. 3.

The seat proper 12 is slidably mounted on the floor 22 using a runner 24including a stationary bar 26, which is itself secured to the floor 22.

The seat proper 12 is connected to the stationary bars 26 by a pair offront legs 28 and a pair of rear legs 30, disposed on either side of theseat proper 12 and joined together by crosspieces. These crosspiecespresent a substantially flat portion forming part of a disk with itsrounded side facing towards the vehicle cabin in such a way as to limitsnagging on other elements.

The front legs 28 are L-shaped, each comprising a first limb 28 a thatextends vertically and a second limb 28 b that extends horizontallyalong the axis X along the stationary bar 26.

The second limb 28 b of the L-shaped leg 28 extends along the axis X,parallel to the stationary bar 26 of the runner 24, between a front andrear end, and itself forms a moving bar of the runner 24 that slidesalong the stationary bar 26 in order to enable the seat to be movedlongitudinally along axis X to occupy different positions in thevehicle. The rear leg 30 is secured to a bottom end on the second limb28 b of front leg 28.

For this purpose, each front leg 28 includes a runner lock known to theperson skilled in the art.

The seat proper includes a cushion 32 secured to a first frame 34 thatis carried by a second frame 36 made of rigid metal and on which theback 18 is mounted.

The first frame 34 is in the form of a metal bucket that has verticalsides 34 a and 34 b on either side of the seat 10. The front edge of thebucket forms an upward fold that forms a safety crosspiece. Thiscrosspiece is adapted to be deformed plastically while absorbing part ofthe mechanical energy due to the inertia of the user in the event of afrontal impact, thereby limiting the forces exerted under the thighs ofthe user during an accident and thus improving safety.

The second frame 36 comprises two metal cheekplates on either side ofthe seat.

The first frame 34 presents a front part and a rear part whose sides 34a and 34 b are connected to the second frame 36 by respective front andrear links 38 and 40 on either side of the seat proper 12. In thedescription below, only one side of the seat proper 12 is described tofacilitate the reader's understanding, the other side being symmetricalabout a central longitudinal axis of the seat.

The front link 38 and the rear link 40 present respective top portions38 a and 40 a that are pivotally mounted on the first frame 34 by meansof first pivots. They also have respective bottom portions 38 b and 40 bpivotally mounted on the second frame 36 by means of second pivots. Thefirst and second pivots present axes of rotation in alignment onopposite sides of the seat.

Since the second frame 36 is secured to the floor 22 of the vehicle viafront legs 28 and rear legs 30, only the top portions 38 a and 40 a ofthe links 38 and 40, connected to the seat proper 12, can move relativeto the second frame 36 from an initial position rearwards or forwards toa retracted position by the links 38 and 40 pivoting about the first andsecond pivots.

The two links 38 and 40 are positioned so that they pivot in the sameangular direction, between the initial position in which the seat 10 isdeployed and corresponding to a first position of the first frame 34,shown in FIG. 1, and a second position in which the seat is folded downand corresponding to a second or stool position of the first frame,shown in FIG. 2. In the first position, the first frame 34 and thus theseat proper 12 are higher than in the second position. While the seat ismoving, the top portions of the links 38 a and 40 a describe downwardcircular arcs.

FIG. 2 shows the seat 10 when the links 38 and 40 have turned counterclockwise. In a variant of the invention, they could turn in theopposite direction, with the seat then being moved backwards.

In the normal-use position of the seat, the links 38 and 40 are held intheir initial high position, and as a result the first frame 34 isblocked in its first position, by means of a locking device, which isshown diagrammatically in the accompanying figures.

This mechanism comprises two blocking members formed by two hooks 44,each positioned on the rear portion on either side of the seat proper,and only one of which is visible in the accompanying figures. The hook44 is pivotally mounted on the first frame 34 to pivot between ablocking position in which it is adapted to receive the top portion ofthe rear link 40 a in its initial position to prevent it from tiltingforwards, and a released position in which it allows the rear link 40 tomove forwards towards its retracted position.

The hook 44 is pivotally mounted relative to the first frame 34 about anaxis parallel to the axis of rotation of the links. Thus, when the hook44 is pivoted, the top portion of the rear link 40 a is released, and isthen free to pivot forwards.

The pivoting of the hook 44, and as a result, the release of rear link40 can be achieved via a linking mechanism, such as a cable 46 thatextends between the back 18 and said hook 44, the mechanism beingcontrolled by tipping the back 18 down towards the seat proper 12.

A spring 48 urges the rear link 40 towards its retracted position.

Thus, when the back 18 is tipped forwards, the hook 44 is automaticallypivoted and releases the rear link, which is driven forwards by thespring 48. Thus the seat proper is driven forwards and loweredautomatically while the back 18 of the seat 10 is being tipped forwardsand comes close to the stool position. This gives a seat in thefolded-down position that takes up less space than prior-art seats.

A stop secured to the first frame 34 limits how far the top portion 38 aof the front link 38 can move and ensures the seat proper 12 remainsstable when the seat is in the stool position. This stop takes the formof a through-stud projecting from the first frame.

The second frame 36 is pivotally mounted on the front leg 28, to pivotabout a transverse axis Y2 in a manner that brings the seat into thefolded-up shown in FIG. 3. To do this, the user releases the rear leg30, which has its bottom end secured to the second limb 28 b of thefront leg 28 via a releasable hook of the type known to the personskilled in the art.

To put the seat back into its normal, deployed position, the user tiltsthe back 18 backwards, its hinge automatically re-locking when itreaches a position inclined at a determined angle, close to asubstantially horizontal position such as the stool position. A usersitting on the seat 10 pushes the seat proper backwards, by using theirown legs, so that the first frame 34 moves backwards to its firstposition. During this movement the rear links 40 slide on a cam surface50 of the hook 44, which pivots to its release position, leaving therear link 40 to move to its initial high position. Then the hook 44locks the pivoting movement of rear link 40 in its initial position tohold the first frame 34 in the first position, and as a result, holdingthe seat proper 12 in its normal-use position.

1. A Vehicle seat comprising: a back and a seat proper comprising acushion secured to a first rigid frame, the first frame being itselfsupported on both sides of the seat proper by a second rigid frame, thefirst frame being movable between a first position and a second positionrelative to the second frame; and the first frame incorporating a frontportion and a rear portion, each connected to the second frame by meansof at least one link, the link presenting firstly a bottom portionpivotally mounted on the second frame and secondly a top portionpivotally mounted on the first frame and movable relative to the secondframe from an initial position, corresponding to the first position ofthe first frame, to a retracted position corresponding to the secondposition of the first frame, the link being designed so that the secondposition of the first frame is lower than the first position; the seatbeing characterized: in that the back is pivotally mounted directly onthe second frame; in that a locking device is adapted to block the firstframe in the first position; and in that a linking mechanism is adaptedto release the locking device while the back is being tilted downtowards the seat proper.
 2. A vehicle seat according to claim 1, inwhich the first frame is a sheet metal bucket.
 3. A vehicle seataccording to claim 1, in which the second frame comprises twocheekplates that surround the bucket.
 4. A vehicle seat according toclaim 1, in which the locking device comprises at least one blockingmember pivotally mounted on the first frame to pivot between a blockingposition in which it holds one of the links in its initial position anda release position in which it enables the link to move, the blockingmember presenting a cam surface on which the link slides, moving themember towards its release position while the first frame is being movedtowards the first position.
 5. A vehicle seat according to claim 1,including a spring that urges the link towards its retracted position.6. A vehicle seat according to claim 1, in which the seat proper issupported by two front legs and two rear legs and in which each secondframe is mounted on a front leg in such a way that it pivots.
 7. Avehicle seat according to claim 1, in which the second position isfurther forwards than the first position.
 8. A vehicle seat according toclaim 1, in which the seat back can be folded down onto the seat properin a substantially horizontal stool position and in which the release ofthe locking device is achieved when the back is close to this stoolposition.
 9. A vehicle seat according to claim 1, in which the linkingmechanism is a cable that extends between the back and the lockingdevice.